Build fails on sparc with "symbol strnlen: referenced symbol not found". Two issues:
- In bson-config.h we define BSON_HAVE_STRNLEN, however bson-string.c uses HAVE_STRNLEN
- mongoc-cursor.c has another call to strnlen which is not conditioned at all.
Build fails on sparc with "symbol strnlen: referenced symbol not found". Two issues: